Yeah, I'm figuring it was that because whenever you quote a post, it puts it back into the formatting that was used, so it'll show up with all the formatting the original poster used. With HTML, it does the same thing, but a new post defaults to using only UBBCode, rendering HTML into "just more text".

This post is mostly directed at the less web-savvy users. For you and I, it might be something simple, but this should hopefully break it down for others without as much background using computers.